U.S. patent application number 11/213197 was filed with the patent office on 2006-03-02 for rotatable earth pin in an electrical plug.
This patent application is currently assigned to Astec International Limited. Invention is credited to Gurmeet S. Bhutani.
Application Number | 20060046541 11/213197 |
Document ID | / |
Family ID | 35198584 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060046541 |
Kind Code |
A1 |
Bhutani; Gurmeet S. |
March 2, 2006 |
Rotatable earth pin in an electrical plug
Abstract
An electrical plug is disclosed having a rotatable earth pin
that can be folded into a plug body by rotating the rotatable earth
pin from an unfolded position to a folded position. In the unfolded
position, the rotatable earth pin is interlocked with the plug body
through a locking tab on a snap lock that latches onto the plug
body. To release the rotatable earth pin from its unfolded
position, pressure is exerted onto the locking tab to release the
snap lock, which allows the rotatable earth pin to move and rotate
to a folded position. Locking pins and associated grooves
releasably retain the rotatable earth pin in its folded
position.
Inventors: |
Bhutani; Gurmeet S.; (Pasig,
PH) |
Correspondence
Address: |
NIXON PEABODY, LLP
401 9TH STREET, NW
SUITE 900
WASHINGTON
DC
20004-2128
US
|
Assignee: |
Astec International Limited
|
Family ID: |
35198584 |
Appl. No.: |
11/213197 |
Filed: |
August 25, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60605727 |
Aug 30, 2004 |
|
|
|
Current U.S.
Class: |
439/131 |
Current CPC
Class: |
H01R 35/04 20130101 |
Class at
Publication: |
439/131 |
International
Class: |
H01R 13/44 20060101
H01R013/44 |
Claims
1. An electrical plug, comprising: a plug body having a first
conductive blade and a second conductive blade; and a rotatable
earth pin having an arm and an earth pin blade, the arm having a
pair of pivot pins on the sides thereof for enabling the rotatable
earth pin to rotate between an unfolded position and a folded
position, the rotatable earth pin enabled to be releasably locked
in said folded position by a pair of locking pins located on the
sides of said arm at a position spaced from said pivot pins.
2. The electrical plug of claim 1, wherein, when the rotatable
earth pin is in said folded position, the pair of locking pins
interlocks within grooves in said plug body until manually released
by the user.
3. The electrical plug of claim 1, further comprising a snap lock
formed on the front surface of said arm such that, when the
rotatable earth pin is in said unfolded position, said snap lock is
latched to said plug body to releasably affix the rotatable earth
pin in said unfolded position.
4. The electrical plug of claim 3, wherein said snap lock includes
a flexible appendage having a locking press tab and wherein the
front surface of said arm has side locks to prevent backward
movement of the earth pin when said plug is plugged into an
electrical socket.
5. The electrical plug of claim 4, wherein, as pressure is exerted
on the locking press tab, the rotatable earth pin is released from
its unfolded position on the plug body, to enable the earth pin to
be manually rotated to said folded position.
6. The electrical plug of claim 5, wherein the distal end of the
rotatable earth pin blade protrudes slightly from the rear surface
of the plug body when said rotatable earth pin is in said folded
position and, as pressure is exerted on said distal end, the
rotatable earth pin is released from said folded position to enable
the earth pin to be manually rotated to said unfolded position.
7. The electrical plug of claim 1, wherein the plug body has a
front piece and a back piece.
8. The electrical plug of claim 7, wherein the first and second
conductive blades extend outwardly from the front piece.
9. The electrical plug of claim 8, wherein fasteners join said
front piece to said back piece.
10. An electrical plug, comprising: a plug body having a front
piece with a first conductive blade and a second conductive blade
extending outwardly therefrom, a back piece, and fasteners joining
the front piece to the back piece; and a rotatable earth pin having
an arm and an earth pin blade, the arm having a pair of pivot pins
on the sides of the rotatable earth pin for rotating the rotatable
earth pin approximately 180.degree. from an unfolded position to a
folded position, the rotatable earth pin enabled to be releasably
locked in said folded position by a pair of locking pins located on
the sides of said rotatable earth pin arm.
11. The electrical plug of claim 10, wherein, when the rotatable
earth pin is in said folded position, the pair of locking pins
interlocks within grooves in said plug body until manually released
by the user.
12. The electrical plug of claim 10, further comprising a snap lock
formed on the front surface of said arm such that, when the
rotatable earth pin is in said unfolded position, said snap lock is
latched to said plug body to releasably affix the rotatable earth
pin in said unfolded position.
13. The electrical plug of claim 12, wherein said snap lock
includes a flexible appendage having a locking press tab and
wherein the front surface of said arm has side locks to prevent
backward movement of the earth pin when said plug is plugged into
an electrical socket.
14. The electrical plug of claim 13, wherein, as pressure is
exerted on the locking press tab, the rotatable earth pin is
released from its unfolded position on the plug body to enable the
earth pin to be manually rotated to said folded position.
15. The electrical plug of claim 14, wherein the distal end of the
rotatable earth pin blade protrudes slightly from the rear surface
of the plug body when said rotatable earth pin is in said folded
position and, as pressure is exerted on said distal end, the
rotatable earth pin is released from said folded position to enable
the earth pin to be manually rotated to said unfolded position.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
application Ser. No. 60/605,727 filed Aug. 30, 2004.
FIELD OF INVENTION
[0002] The invention relates generally to electrical plugs and more
particularly to electrical plugs having movable earth pins.
BACKGROUND OF THE INVENTION
[0003] A wide variety of electrical devices typically draw AC power
from a commercial source, usually delivered through a wall
receptacle or socket, via a corresponding electrical plug.
[0004] A conventional electrical plug typically has a pair of
conductive power pins for insertion into corresponding female
connectors in the socket. The plug typically also includes an earth
or ground pin that is inserted into a corresponding female
connector in the socket that is coupled to ground. In certain
countries, the earth pin is slightly longer than the power pins and
also functions to open a spring loaded shutter in the socket, to
allow insertion of the power pins into their respective female
connectors in the socket. This safety feature thus requires that an
earth pin be included in all plugs even when there is no need for a
ground connection.
[0005] Battery chargers comprise one type of electrical device
whose plugs typically do not require an earth or ground connection.
However, to provide the shutter opening function, a dummy ground
pin still needs to be provided. Such prior art earth pins are
usually in a fixed position on the electrical plug, which makes the
electrical plug unnecessarily bulky.
[0006] One prior art method for repositioning the earth pin in an
electrical plug is to connect the earth pin to a hinge, to enable
the pin to be rotated between two positions, an open position and a
stored position. The pin is rotated 90.degree. between these two
positions about the axis of the hinge.
[0007] Consumers of electrical products in recent times have shown
a desire for more compact designs. Accordingly, there is a need to
reduce the amount of space taken up by an electrical plug when not
in use, to enable the plug to be more compact.
SUMMARY OF THE INVENTION
[0008] The present invention is an electrical plug having a
rotatable earth pin that can be folded into a plug body by rotating
the rotatable earth pin from an unfolded position to a folded
position. In the unfolded position, the rotatable earth pin is
interlocked with the plug body through a locking tab with a snap
lock that latches onto the plug body. To release the rotatable
earth pin from an unfolded position, a pressure is exerted onto the
locking tab, which allows the rotatable earth pin to move and
rotate to a folded position.
[0009] Broadly stated, the electrical plug comprises: a plug body
having a first conductive blade and a second conductive blade; and
a rotatable earth pin having an arm and an earth pin blade, the arm
having a pair of pivot pins on the sides thereof for enabling the
rotatable earth pin to rotate from an unfolded position to a folded
position, and the rotatable earth pin enabled to be releasably
locked in said folded position by a pair of locking pins located on
the sides of said rotatable earth pin arm at a position spaced from
said pivot pins.
[0010] The other structures and methods regarding to the present
invention are disclosed in the detailed description below. This
summary does not purport to define the invention. The invention is
defined by the claims. These and other embodiments, features,
aspects, and advantages of the invention will become better
understood with regard to the following description, appended
claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view of a rotatable earth pin plug having a
rotatable earth pin that is shown being unfolded from a plug body
in accordance with the present invention.
[0012] FIG. 2 is an exploded perspective view of the front and
right side of the rotatable earth pin plug in accordance with the
present invention.
[0013] FIG. 3 is an exploded perspective view of the back and right
side of the rotatable earth pin plug in accordance with the present
invention.
[0014] FIGS. 4A-4B are perspective views respectively illustrating
the front and left side and front and right side of the rotatable
earth pin with the various locking mechanisms in accordance with
the present invention.
[0015] FIG. 5 is a cross-sectional left side view of the electrical
plug where the rotatable earth pin is in an interlocked, unfolded
position in accordance with the present invention.
[0016] FIG. 6A is a perspective back and right side view of the
rotatable earth pin plug showing the rotatable earth pin in its
interlocked, unfolded position in accordance with the present
invention.
[0017] FIG. 6B is a cross-sectional right side view of the
electrical plug where the rotatable earth pin is in its
interlocked, unfolded position in accordance with the present
invention.
[0018] FIG. 7A is a cross-sectional left side view of the
electrical plug where the rotatable earth pin is in a folded
position in accordance with the present invention.
[0019] FIG. 7B a bottom view of the electrical plug illustrating
the rotatable earth pin in its folded position in accordance with
the present invention.
[0020] FIG. 8A is a perspective view of the back and left side of
the rotatable earth pin plug with the rotatable earth pin in its
interlocked, unfolded position in accordance with the present
invention.
[0021] FIG. 8B is a perspective cross-sectional view through the
back and left side of the rotatable earth pin plug with the
rotatable earth pin in its interlocked, unfolded position and
showing the locking mechanism of the rotatable earth pin in
accordance with the present invention.
[0022] FIG. 9A is a perspective view of the back and left side of
the electrical plug where the rotatable earth pin is in its
interlocked, unfolded position in accordance with the present
invention.
[0023] FIG. 9B is an end view of the electrical plug showing the
rotatable earth pin in its folded position and showing the pin
locking mechanism in accordance with the present invention.
[0024] FIGS. 10A-10B are a partial perspective view and a side
view, respectively, of the rotatable earth pin plug showing the
side locks mechanism in accordance with the present invention.
[0025] FIGS. 11A-11B are perspective views of the rotatable earth
pin in a folded position in accordance with the present
invention.
[0026] FIGS. 12A-12B are end views of the rotatable earth pin plug
showing the earth pin in an unfolded position and in a folded
position, respectively, in accordance with the present
invention.
[0027] Reference symbols or names are used in the figures to
indicate certain components, aspects or features therein, with
reference symbols common to more than one figure indicating like
components, aspects of features shown therein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] Referring now to FIGS. 1-3, there are shown a side view and
exploded perspective views of a rotatable earth pin plug 100 in
accordance with the present invention. The rotatable earth pin
comprises a rotatable earth pin 120 for folding into a plug body
110 having a first conductive blade 106 and a second conductive
blade 108. The rotatable earth pin 120 is able to rotate preferably
a full 180.degree. so that it folds into a channel 109 and passage
130 of the plug body 110 without any protrusions in either the
x-direction or y-direction of the rotatable earth pin 120. The
earth pin plug is shown in its unfolded position at 120a and in
phantom to illustrate its movement from its unfolded position to
its folded position, shown at 120b.
[0029] Exploded views of the rotatable earth pin plug 100 are shown
in FIGS. 2-3. The plug body 110 has a front piece 111 having the
channel 109 and the first and second conductive blades 106 and 108
extending outwardly therefrom, a back piece 112, and a pair of
screws 115 or other suitable fastener to join front piece 111 to
back piece 112. Earth pin 120 includes opposite pivot pins 126a and
126b (See also FIGS. 4A-4B) that define the axis of rotation of
earth pin 120 once earth pin 120 is assembled within plug body
110.
[0030] FIGS. 4A-4B are perspective views of the earth pin 120
showing the various locking mechanisms in the rotatable earth pin
100 of the present invention. The earth pin 120 is an L shape
formed by an arm 122, preferably of a flexible material, and an
earth pin blade 128. Earth pin 120 is preferably a dummy ground
pin, to provide the shutter opening function described above. The
front surface of arm 122 includes side locks 124 and a flexible
appendage 129 having grooves 121, a locking press tab 123 and a
snap lock 125. The sides of arm 122 include the pivot pins 126a and
126b. A folded locking pin 127a and a folded locking pin 127b are
formed on respective upper sides of arm 122. The side locks 124 are
used to prevent backward movement of the earth pin 120 while earth
pin plug 100 is being plugged into an electrical source (not
shown). The snap lock 125 snaps into the plug body 110 for fixing
the rotatable earth pin 120 in its unfolded position. To unlock the
rotatable earth pin 120, the locking tab 123 is pressed down toward
the grooves 121 to cause the snap lock 125 to clear the plug body
110, as described below, and thereby enable manual rotation of the
rotatable earth pin 120 by 180.degree. or so to its folded position
where locking pins 127a and 127b lock into the plug body 110 to fix
the earth pin 120 in its folded position.
[0031] Note that, in its folded or stowed position, earth pin 120
provides an indication that an attempted insertion of plug 100 into
a socket is incorrect. That is, the front surface of arm 122
protrudes out from plug body 110 in the direction of blades 106 and
108 to restrict the complete insertion of plug 100 into the socket.
Consequently, even where the socket does not include a shutter
opening function, earth pin 120 prevents the full insertion of plug
100 into a socket when the rotatable earth pin 120 is in its folded
position.
[0032] Turning now to FIG. 5, there is shown an electrical plug 100
in which the rotatable earth pin 120 is in its unfolded position.
The snap lock 125 of the flexible arm 122 latches onto the plug
body 110 in the unfolded position. As can be seen in this figure,
the side locks 124 of the flexible arm 122 also mate with the
surface of the plug body 110 to prevent backward movement of earth
pin while plugging into an electrical source (not shown).
[0033] In FIGS. 6A-6B, there are shown a perspective view and a
cross-sectional side view, respectively, of the electrical plug 100
in the unfolded position. These figures illustrate how to unlock
earth pin 120 from its unfolded position. A pressure is exerted on
the locking tab 123 to release the rotatable earth pin 120 from the
plug body. When the earth pin 120 is released, it can be manually
rotated by 180.degree. to place the electrical plug 100 and its
earth pin 120 in a folded position, as shown in FIGS. 7A-7B. Earth
pin blade 128 is within passage 130 and protrudes slightly beyond a
rear surface of the plug body 120. Therefore, a user can press on
the tip 131 of the earth pin blade 128 in order to release the
rotatable earth pin 120 from its folded position.
[0034] To retain earth pin 120 in its folded position, locking pins
127a and 127b interlock with grooves 150a and 150b, respectively,
as shown in FIGS. 8A-8B, FIGS. 9A-9B, and FIGS. 4A-4B. When the
rotatable earth pin 120 interlocks with plug body 110 by means of
the locking pins 127a and 127b with the grooves 150a and 150b on
the plug body 110, it is thereby releasably maintained in its
folded position until manually released by a user.
[0035] In FIGS. 10A-10B, there are shown perspective views of the
electrical plug showing the side locks 124. The side locks 124 in
the rotatable earth pin 120 prevent the rotatable earth pin 120
from bending backward during plugging into an electrical source.
The direction of the pressure during plugging is shown by arrow
160. The side locks 124 operate like an edge stop, and push against
the plug body 110 to prevent the rotatable earth pin 120 from
bending backward.
[0036] FIGS. 11A-11B are perspective views of the electrical plug
in a folded position. An end view of the electrical plug 100 in the
unfolded position having the channel 109 and passage 130 for
storing rotatable earth plug 120 is shown in FIG. 12A, and an end
view of the electrical plug 100 in the folded position is shown in
FIG. 12B.
[0037] One of ordinary skill in the art should recognize that the
present invention can be applied to different types of electrical
plugs in various regions or countries. One suitable application is
on plugs used in the United Kingdom.
[0038] Those skilled in the art can now appreciate from the
foregoing description that the broad techniques of the embodiments
of the present invention can be implemented in a variety of forms.
Therefore, while the embodiments of this invention have been
described in connection with particular examples thereof, the true
scope of the embodiments of the invention should not be so limited
since other modifications, whether explicitly provided for by the
specification or implied by the specification, will become apparent
to the skilled practitioner upon a study of the drawings,
specification, and following claims.
* * * * *